Moonstone vs Opal

Comparing Moonstone and Opal — two gemstones with a strikingly similar appearance. On the Mohs scale, Moonstone rates 6.0 and Opal rates 5.0. In terms of price, Moonstone falls in the moderately priced range and Opal in the budget-friendly range.

Property Moonstone Opal
Category Semi-Precious Gems Semi-Precious Gems
Primary Color white white
Mohs Hardness 6.0–6.5 5.0–6.5
Specific Gravity 2.56 1.98
Refractive Index 1.518 1.37
Crystal System Monoclinic Amorphous
Luster Vitreous
Chemical Formula
Price Tier Moderate ($50-500/ct) Budget (< $50/ct)
Daily Wear No No

Key Differences

  • {'gem_a': '6.0', 'gem_b': '5.0', 'property': 'Hardness (Mohs)'}
  • {'gem_a': 'Monoclinic', 'gem_b': 'Amorphous', 'property': 'Crystal System'}
  • {'gem_a': '2.56', 'gem_b': '1.98', 'property': 'Specific Gravity'}
  • {'gem_a': '1.518', 'gem_b': '1.37', 'property': 'Refractive Index'}
  • {'gem_a': 'Vitreous', 'gem_b': 'N/A', 'property': 'Luster'}
  • {'gem_a': 'moderate', 'gem_b': 'budget', 'property': 'Price Range'}
  • {'gem_a': 'No', 'gem_b': 'No', 'property': 'Daily Wear'}

When to choose Moonstone

Elija Moonstone cuando busque mayor dureza y durabilidad para uso diario. Ideal para joyería de compromiso y uso cotidiano.

When to choose Opal

Elija Opal cuando prefiera un precio más accesible. Ideal para joyería cotidiana y piezas especiales.

Frequently Asked Questions

Which is harder, Moonstone or Opal?
Moonstone is harder at 6.0-6.5 on the Mohs scale, compared to Opal at 5.0-6.5. This makes Moonstone more resistant to scratching. Moonstone requires more careful handling and is not ideal for daily wear, while opal requires more careful handling and is not ideal for daily wear.
Is Moonstone more expensive than Opal?
Yes, Moonstone is generally more expensive. Moonstone is classified as moderately priced ($50-500/ct) with prices around moderately priced ($50-500/ct), while Opal is budget-friendly (under $50/ct) at budget-friendly (under $50/ct).
Should I choose Moonstone or Opal for an engagement ring?
Neither Moonstone nor Opal is ideal for an engagement ring worn daily. Moonstone (6.0-6.5 Mohs) is the more durable of the two, while Opal (5.0-6.5 Mohs) is softer. If you choose either, consider a protective setting like a bezel.
How can I tell Moonstone and Opal apart?
There are several visual cues: both appear white, but often in different saturations; Moonstone (RI 1.518-1.527) shows more brilliance than Opal (RI 1.37-1.52); they have different crystal systems — Moonstone is Monoclinic and Opal is Amorphous. A gemologist can confirm identification using refractive index testing.
Is Moonstone a good alternative to Opal?
Moonstone is actually more expensive than Opal, so it functions as a premium upgrade rather than an alternative. Moonstone is moderately priced ($50-500/ct) versus Opal at budget-friendly (under $50/ct). If budget is a concern, Opal offers a similar look at a lower price.

Related Comparisons

Back to all gems